Gas treatment apparatus



Nov. 16,1965 R. R. CALACETO 3,218,047

GAS TREATMENT APPARATUS Original Filed Nov. 28, 1958 2 Sheets-Sheet 1INVENTOR. RALPH R. CALACZETO ATTORNEYS Nov. 16, 1965 c c o 3,218,047

GAS TREATMENT APPARATUS Original Filed Nov. 28, 1958 2 Sheets-Sheet 2Fla.4-

se 12 58 5s 5s IN V EN TOR. PALPH R. CALACETO ATTORNEYS United StatesPatent Original application Nov. 28, 1958, Ser. No. 776,797. Divided andthis application Sept. 26, 1962, Ser. No.

1 Claim. (Cl. 261-71) This application is a divisional application of myc0- pending application Serial No. 776,797, filed November 28, 1958, andnow abandoned.

This invention relates to an apparatus for treating gases andparticularly for separating and collecting particles carried by gases.

In the treatment of gases, it has been suggested that separation of theparticles from the gases can be achieved by impinging jets of liquidsuch as water into contact with the gases.

It is an object of this invention to provide an apparatus wherein a moreefiicient separation of particles of both micron and submicron size isachieved by utilizing jets of liquid such as water.

In the drawings:

FIG. 1 is a part sectional elevation of an apparatus embodying theinvention.

FIG. 2 is a fragmentary sectional view taken along the line 2-2 of FIG.1.

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 1 showinganother arrangement of nozzle assemblies.

FIG. 4 is a side elevational view of one of the nozzle assemblies shownin FIG. 3.

FIG. 5 is a fragmentary sectional view taken along the line 55 in FIG.4.

Referring to FIG. 1, gas which is to be treated is introduced through aninlet pipe to impact type scrubber 11 and then passes through aconnecting pipe 12 to a cyclonic type scrubber 13. The particles in thegas which are of micron or submicron size are agglomerated in impactscrubber 11. The agglomerated particles pass to the cyclonic scrubber 13where they are separated from the gases. Small agglomerates which may beone or two microns in size may be further agglomerated by the action ofthe liquid in the cyclonic scrubber 13 and are separated from the gases.Otherwise, the particles which are one or two microns in size may bedischarged with the gases.

As shown in FIG. 1, impact scrubber 11 comprises an open endedcylindrical thimble 15 which is surrounded by a dome section 16.Scrubber 11 also includes an inverted frusto-conical section 17 whichconverges down- Wardly from the periphery of the dome section 16 from apoint adjacent the lower end of thimble 16 and a diverging section 18extending downwardly from the lower end of the frusto-conical section 17thereby forming a throat 19.

Means are provided for introducing a plurality of jets of water intoimpactor 11 and comprise a plurality of nozzles circumferentially spacedin dome 16 with their axes parallel to the axis of thimble 15. By thisarrangement the gases are cooled in the area of the thimble 15 byindirect contact or conduction through the thimble wall. As a result, inthe area of the thimble wall, the cooling of the gases is performed in asensible manner. As the water moves below the lower end of the thimble,it comes in direct and intimate contact with the hot gases therebycausing further cooling of the gases by adiabatic saturation.

As the gases approach the throat 19, their velocity is increased.Increased velocity in the area of contact with the liquid at the throat19 is sufiiciently great to agglomerate the submicron particles in thegases.

3,218,047 Patented Nov. 16, 1965 Although I do not wish to be bound bythe theory involved, in my opinion, the very desirable results ofagglomeration of the submicron particles in my invention are achieved bythe interaction of the liquid and the gases at the throat 19. The liquidfrom the nozzles 20 travels downwardly along the converging wall 17 ofthe impact scrubber 11 and tends to close or restrict the throat 19. Thegases containing the particles which are to be removed move downwardlyand as they approach the throat 19 their velocity is substantiallyincreased. The gases moving at high velocity atomize the liquid at thethroat 19 into droplets which are of sufficiently fine size that theywill collide with the particles in the gases and wet these particles sothat they will readily agglomerate.

The novel cooling action of the impact scrubber provides for asaturation of the gas at a lower temperature. If the liquid emanating inthe jets 20 contacted the hot gases directly then a higher adiabaticsaturation temperature would result. This may be readily understood byreferring to psychrometric tables. For example, referring to such tablesshows the following:

(A) Gas at 1800 F. has a humidity of 0.14 pound of moisture per pound ofdry gas. Upon adiabatic saturation the gas cools to F. with a humidityof 0.657 pound of moisture per pound of dry gas.

(B) Gas at 1800 F. cooled sensibly to 600 F. will maintain a humidity of0.14 pound of moisture per pound of dry gas. Upon adiabatic saturation,the temperature is reduced to 158 F. with a humidity of .278 pound ofmoisture per pound of dry gas.

It can be seen that under condition A above approximately 50 percent ofthe total gaseous volume comprises water vapor. This may be contrastedto condition B wherein the gas is initially cooled to 600 F. and theresultant water vapors comprises 30 percent of the total gaseous volume.

It can thus be seen that the impact scrubber 11 may be used not only toefiiciently agglomerate the submicron sized particles in the gases butin addition to cool gases so that they leave the impact scrubber 11 at alower saturation temperature.

The impact scrubber 11 may also be used as a reactor in chemicalprocesses where it is desired to bring a liquid and a gas into intimatecontact.

Although the thimble 15, sections 16, 17 and 18 are shown as beingcircular in cross section, it will be appreciated that the cross sectionof these sections may be changed as long as the relationship andrelative sizes of the sections are retained.

Gas after having been treated in impact scrubbers may be treated in anyconventional liquid-gas separator to re move the agglomerated particlesand liquid from the gases or may be further treated in the cyclonicscrubber 13. When the gases are treated in a cyclonic scrubber 13, theyare caused to enter the scrubber in a tangential direc tion at one endthereof and to move longitudinally thereof in a spiral fashion. As thegases move along the scrubber 13, they are subjected to a plurality ofgenerally radially extending jets from nozzles 50 which are spacedcircumferentially and vertically along the wall of scrubber 13. Anyagglomerated particles from the impact scrubber 11 which are of one ortwo micron size are easily agglomerated in cyclonic scrubber 13 to asize where they are readily separated in the cyclonic scrubber 13. Thegases pass out through the top opening 14 and the liquid which isseparated passes out through the bottom opening 51.

The impact scrubbers shown in FIGS. 1 and 2 may be used in the treatmentof gases in various manners.

The impact scrubbers may also be used as de-dusters a) to removeparticles which are carried by the gases. These particles may comprisemetallurgical or nonmetallic materials. When used as a de-duster, theapparatus eliminates the accumulation or caking of sludge in the area ofcontact of the liquid with the gas. Although I do not wish to be boundby the theory involved, in my opinion, the beneficial results achievedin the retardation of sludge such as might occur by contact of hot gaseswith liquid at a lower temperature is achieved because the liquid movingalong the converging Wall 17 tends to lubricate the wall and prevent theaccumulation of sludge along the wall.

The impact scrubbers 11 are most effectively used as agglomerators forcoalescing the submicron particles in the gases into larger sizes sothat they can be readily separated from the gases. Accordingly, theoutlet of the diverging section 18 of impact scrubber 11 may beconnected to a separator of conventional construction.

The impact scrubbers 11 thus may be used independently of the cyclonicscrubbers 13.

Cyclonic scrubbers 13 are used to cool the gases and in addition may beused independently to agglomerate and remove particles of micron size orlarger from gases. Cyclonic scrubbers 13 are of generally conventionalcon: struction except for the specific arrangement of the nozzles 50. Asshown in FIGS. 3, 4 and 5, the nozzles are provided in vertical banks atcircumferentially spaced points along the periphery of the jet scrubber13. The nozzles 50 have an axial passage as shown in FIG- URE 5. Thenozzles communicate with the header to which water or other liquid issupplied through supply pipes 56. A valve 57 is provided in each supplypipe 56, as is a pressure gauge 58 (FIG. 1). Access openings 59 areprovided in axially aligned relationship to each nozzle 50. Each opening59 is closed by a removable plug 60.

By this arrangement, if for any reason a nozzle 50 becomes plugged, theplugging will be registered by an increase in pressure on one of thegauges 58. The operator may then close the corresponding valve 57,remove the plug 60 and clean the nozzles 50 in the particular header 55without interrupting the operation of the jet scrubber 13. Thisarrangement thus permits the jet scrubber to be operated and maintainedwithout interrupting its function in any material degree.

The principal function of the cyclonic scrubber 13 is to handle the morecommon de-dusting problems Where gases carry micron size particles.

I claim:

In a gas treatment apparatus, the combination comprising means defininga chamber having a wall, means defining a tangential gas inlet in thechamber, a gas outlet in the chamber and spaced from said inlet, aplurality of circumferentially and vertically spaced nozzle assembliesmounted on the wall of the chamber between the gas inlet and outlet,each nozzle assembly comprising a plurality of vertically spaced nozzlesin said Wall, each of said nozzles having an axial passage therethrough,means surrounding and cooperating with a portion of said Wall to definea plurality of headers, each header surrounding one of said nozzleassemblies, means for supplying liquid to each of said headers,removable closure means on each of said headers axially aligned with andoverlying each of said nozzles and providing access to each of saidnozzles, and valve means connected to each of said means for supplyingliquid.

References Cited by the Examiner UNITED STATES PATENTS 630,506 8/1899Hirzel. 1,001,929 8/1911 Collins 210- 1,543,941 6/ 1925 Mathesius.1,753,522 4/1930 Larsen 239 2,509,817 5/1950 Foreman 55-236 2,860,78411/1958 Breithaupt 210-90 FOREIGN PATENTS 176,626 12/ 1906 Germany.

HARRY B. THORNTON, Primary Examiner.

RONALD R. WEAVER, Examiner.

